In the food context, "sliced" usually refers to food items that have been cut into thin, flat pieces.
Here are some examples of sliced foods:
Bread: Sliced bread is a common staple in many households, and is often used for sandwiches and toast.
Cheese: Many types of cheese are sold in pre-sliced form, including cheddar, Swiss, and provolone.
Meat: Sliced meats are often used in sandwiches